The present disclosure relates to databases, and more specifically, to identifying database queries that are likely to have an adverse impact on performance and to handling these queries in a way that reduces a possible adverse impact on performance.
Data is retrieved from a database with a database query. A database query is an expression that is evaluated by a database manager. A database query can be formulated in Structured Query Language (SQL). SQL defines a syntax for generating and processing queries that is independent of the actual structure and format of the database. When the database manager receives a query, it generally produces an access plan to execute the query in the database. A query optimizer or planner can be employed to evaluate expressions in a query, to optimize the query, and to generate the access plan.